But now the cameras turn once again to Charlie Gilmour, a 21-year-old Cambridge student and scion of the Pink Floyd dynasty who today received a 16-month prison sentence after pleading guilty to violent disorder. Gilmour, now sober-suited, bespectacled and freshly shorn, presented a very different figure to the apparently crazed eccentric who was photographed swinging from a union flag on the Cenotaph during the fees protests last December. He was later seen leaping on the bonnet of a Jaguar in a royal convoy taking the Prince of Wales to the royal variety performance, and was also found have also hurled a rubbish bin at the vehicle.

Despite the piecemeal nature of sentencing for those convicted of violent disorder (there are currently no sentencing guidelines in the crown court), comparatively speaking Gilmour's fate seems to be hugely disproportionate and unfair. He simply should not be imprisoned for crimes that hurt nobody. This is a conviction that raises a hackneyed question, so often mooted during the phone-hacking scandal: cui bono?

For the rightwing press Charlie Gilmour was the perfect protester: Oxbridge-educated, strangely attired and shockingly disrespectful of the war dead. He was repellent and ungracious in the eyes of the taxpaying squeezed middle, and he provided the perfect opportunity to discredit the student movement as trustafarian whimsy. And certainly Gilmour did wrong although, having admitted that he had taken LSD and Valium prior to the protests, it's arguable whether he was wholly responsible for some of his more extreme idiocy.

Perhaps, given this background, it was inevitable that Gilmour would be made an example of: living evidence that one does not question the order of things. During the protests he was filmed shouting "they've broken the moral laws, so we must break all the laws!" and this desire to question has cost him, unfairly to my mind, his liberty.

And yet the real tragedy here isn't Gilmour alone. For him at least, depiction of protesters as a sort of hard-left Bullingdon Club is an accurate one. His status and money will see him through. The tragedy is for other protesters who were similarly caught up in the heat of the moment but don't have Gilmour's privilege to fall back on. I'm thinking primarily of Francis Fernie, 20, who was recently convicted of violent disorder for throwing two placard sticks outside Fortnum & Mason at the cuts protest in March. Despite a glowing character reference Fernie was given 12 months in prison – a sentence the judge described as lenient. Fernie's lack of glamour and genuine remorse made him less appealing to tut-tut at than Gilmour, and he was largely ignored by the media.

I fear that over the coming months, stories of protesters watching their futures slipping through their fingers as judges pass merciless sentences on them will become commonplace. Because this is not solely about stamping out the under-represented but over-reported incidents of violent protest. Taking part in peaceful civil disobedience will become much more frightening as those arrested at protests are dragged through the courts system.

And as more and more people are criminalised, what is this all for? If the public sincerely feels safer knowing an LSD-riddled student is behind bars for the next year, we have become a paranoid nation indeed. And nobody benefits from a society where lack of dissent is the result of fear, not happiness.

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